Digital technology based on naval system aiding in the war against breast cancer

Wednesday

Sep 23, 2009 at 12:01 AMSep 23, 2009 at 11:16 PM

Inside Newton-Wellesley Hospital recently, Dr. Alan Semine studied digital mammography results on a flat-screen monitor, then clicked the icon for a computer calculation that the Navy developed to search for underwater mines. Instantly, faint specks that had blended into the larger image moments before and might have gone unnoticed turned into tiny but clear white dots, each a calcium deposit and a possible indicator of cancer.

Michael Morton

Inside Newton-Wellesley Hospital recently, Dr. Alan Semine studied digital mammography results on a flat-screen monitor, then clicked the icon for a computer calculation that the Navy developed to search for underwater mines.

Instantly, faint specks that had blended into the larger image moments before and might have gone unnoticed turned into tiny but clear white dots, each a calcium deposit and a possible indicator of cancer.

Taking a similar step days earlier with the same 40-something patient, Semine and his staff had spotted the warning signs, performed a needle biopsy to confirm their suspicions and removed cancerous tissue from the woman's right breast.

“In a sense, we're just scratching the surface of what the digital world is going to be capable of,” the chief of breast imaging radiology said, shortly after setting a caveat. “Unfortunately, the best we can is more expensive than we can afford or what we want to afford.”

Adapted from naval technology by Advanced Image Enhancement, the algorithm Semine employed will soon be included in all mammogram machines produced by industry leader Hologic of Bedford, at least in its digital models.

Responding to patient demand and widely acknowledged benefits for certain women, roughly half the nation's mammogram clinics now have at least one digital unit, with Newton-Wellesley, MetroWest Medical Center, Milford Regional Medical Center and Marlborough Hospital making a complete transition.

While their images are viewed electronically rather than on film, digital machines look and operate the same as their analog predecessors, with less radiation than the small amount previously emitted. But rather than hold a magnifying glass up to film, doctors can zoom in electronically and quickly tweak contrast, giving them a better view, and can use software aids like the one at Newton-Wellesley.

“It's like night and day, and you wonder how we ever survived with the old stuff,” said Dr. Michael Thompson, a radiologist at The Breast Center at Milford Regional Medical Center.

In 2005, a landmark study by the National Cancer Institute concluded that digital mammography was significantly better at screening those younger than 50, as well as older women still on the cusp of menopause or with dense breast tissue. Two-thirds of the random study participants fell into one of those categories.

When Newton-Wellesley first switched to digital, Semine said, there was an increase in false positives and “callbacks,” times when troubling scan results lead doctors to bring patients back for stressful follow-ups that turn out to be unneeded. But doctors and staff soon got used to the new technology and rates returned to normal.

“Whenever you have something that's new or different, people have to adapt to it,” he said.

The cancer institute study also found no difference in false positive rates between analog and digital mammograms, said Dr. Etta Pisano of the University of North Carolina, the lead investigator and a former Wayland and Newton resident. But in a subsequent cost-benefit paper, Pisano and her colleagues concluded that providing digital mammograms was not cost-effective for women outside the categories specifically cited by the cancer institute study.

For imagining centers like the one at Milford Regional, digital offers ancillary benefits like faster results, better storage and easier forwarding for second opinions. But staff at area centers report that digital demand surged after the cancer institute study, even among women not mentioned as likely beneficiaries.

On the horizon is a new mammogram machine from Hologic, under review by the Food and Drug Administration, that uses a technology called tomosynthesis.

The new design is based on digital machines but pivots around a patient's breast, providing a three-dimensional image rather than a two-dimensional one. Semine said the new technology will allow doctors to separate the breast into on-screen “slices” for a more thorough assessment. But he added that it will carry its own price tag, with the need to determine whether the machines will be used for screening or just diagnosis later.

Regardless of digital or analog, two dimensions or three, Dr. Justine Morris of MetroWest Medical Center's radiology department said women should still do monthly self-exams and annual checkups and not simply rely on mammograms.

“I think it's a misperception of the public that it's 100 percent sensitive,” she said.